Field
Embodiments described generally relate to paperboard blanks for paper products. More particularly, such embodiments relate to paperboard blanks having a shrinkable film adhered thereto and to paperboard containers made from the paperboard blanks and methods for making and using same.
Description of the Related Art
Paperboard is used to make a wide variety of paper products, such as plates, bowls, and cups. Paper products can be insulated in a variety of ways to provide an insulated product, such as an insulated cup for hot or cold beverages. For example, the paper product can be insulated by forming an air gap within a sidewall of the container. The air gap, for example, can be located between a film that forms an inner surface of the sidewall and a paperboard substrate that forms an outer surface of the sidewall. The film can be a shrinkable film that can shrink, e.g., a heat shrinkable film, to form the gap between the film and the paperboard substrate as the film shrinks.
One problem encountered in making an insulated container, such as a cup, with a heat shrinkable film is that the presence of an adhesive used to secure the film to the paperboard substrate along an edge the sidewall that is to be formed into a brim can prevent the formation of a complete brim curl, especially along a portion of the brim that corresponds to a sidewall seam of the container. The uncurled portion(s) of the brim are conventionally referred to in the art as “flagger(s)” or “dog ears.” The brim provides needed structural support to the container and allows lids to be secured thereto, so it is desirable to avoid the formation of flaggers.
There is a need, therefore, for improved containers insulated with shrinkable films and improved methods for securing shrinkable films to paperboard blanks.